The invention relates to a process for reducing hydrogen sulphide in natural gas. When crude oil is extracted, it occasionally comprises large amounts of natural gas. This natural gas may contain a significant amount of hydrogen sulphide (H2S), the H2S content often exceeding 5% and in some cases even 20%—in both cases in relation to volume under standard conditions. This raw gas is dissolved in the crude oil under the high pressure prevailing in oilfields. During extraction, subsequent transportation and refining of the crude oil, this raw gas outgases from the crude oil.
The high H2S content of the raw gas poses a problem, particularly with regard to safety: H2S is a highly poisonous respiratory toxin for humans, animals and plants. In the event of a leak or accident the usually high volumetric flow rates from a well could quickly lead to such a substantial amount of highly toxic H2S being released into the surroundings as to pose a considerable threat of harm to workers and the environment and oil extraction would have to be stopped immediately.
This is an even greater problem when oil extraction is located on an oil platform and the quick evacuation of all personnel in an emergency cannot always be guaranteed. In view of the rough conditions at sea, any process offering a solution should therefore be extremely robust and also space-saving.
Another problem is what to do with the H2S. Admittedly, it could be processed into sulphur dioxide, sulphur and sulphuric acid using a common process. This would however entail immense costs if done on site and, if this were not possible, transport problems would arise.